Color proofing apparatus and method of making color proof

1. An apparatus for making a color proof based on an image signal including yellow, magenta, cyan and black component data Y, M, C, K for each pixel, comprising: an image signal input section to receive the image signal; a black component correcting section to correct the black component data K on the basis of the yellow, magenta and cyan component data Y, M, C for each pixel, wherein the black component correcting section compares a value of the black component data K with a first boundary value and compares a maximum value of the component data Y, M, C with a second boundary value, and when the value of the black component data K is larger than the first boundary value and the maximum value is larger than the second boundary value, the black component correcting section reduces the value of the black component data in accordance with the value of the black component data K and the maximum value, wherein the first boundary value is a value not smaller than 50% and smaller than 100%, the second boundary value is a value not smaller than 0% and smaller than 80% as converted into halftone dot area ratio expressed by percent, an image signal output section to output an image signal including yellow, magenta, cyan and corrected-black component data Y, M, C, K′; and a color proof making section to expose a silver halide light sensitive material based on the outputted image signal with a plurality of light sources different in wavelength and to make a color proof sheet for each color of yellow, magenta, cyan and black.

2. The apparatus of claim 1 , wherein the color proof making section comprises a halftone dot generating section to generate and output halftone dot image data of halftone dot area ratios on the basis of the yellow, magenta, cyan and corrected-black component data Y, M, C, K′, and the color proof making section conducts exposing based on the halftone dot image data.

3. The color proofing apparatus of claim 2 , wherein the black component correcting section reduces the value of black component data by at most 10% of the value of black component data K before corrected.

4. The apparatus of claim 1 , further comprising: a characteristic correcting section to correct at least one of a gradation correction and a color tone characteristic of the image signal.

5. The apparatus of claim 4 , wherein the black component correcting section corrects the black component data K after the characteristic correcting section corrects one of the gradation correction and the color tone characteristic of the image signal.

8. A method for making a color proof based on an image signal including yellow, magenta, cyan and black component data Y, M, C, K for each pixel, comprising the steps of: receiving the image signal; correcting the black component data K on the basis of the yellow, magenta and cyan component data Y, M, C for each pixel, wherein the correcting step compares a value of the black component data K with a first boundary value and compares a maximum value of the component data Y, M, C with a second boundary value, and when the value of the black component data K is laroer than the first boundary value and the maximum value is larger than the second boundary value, the correcting step reduces the value of the black component data in accordance with the value of the black component data K and the maximum value, wherein the first boundary value is a value not smaller than 50% and smaller than 100%, the second boundary value is a value not smaller than 0% and smaller than 80% as converted into halftone dot area ratio expressed by percent, outputting an image signal including yellow, magenta, cyan and corrected-black component data Y, M, C, K′; exposing a silver halide light sensitive material based on the outputted image signal with a plurality of light sources different in wavelength; and making a color proof sheet for each color of yellow, magenta, cyan and black.

9. The method of claim 8 , wherein the black component correcting step reduces the value of black component data by at most 10% of the value of black component data K before corrected.